If there are dotted lines/blue dotted lines/black lines/gray lines after printing with the Xiaomi Portable Photo Printer 1S, it can be due to dust entering the printer. You can use the [Cleaning the print head] function to remove dust from the print head. Place the orange Smart Sheet at the bottom of the photo paper, and the cleaning function will use the orange Smart Sheet to perform cleaning three times.
It is recommended to put the orange Smart Sheet for cleaning after printing every two to three photos. For severe stripes, you can apply alcohol to the orange Smart Sheet for calibration and cleaning.